Floating roof for storage tanks



1937- w. G. M CULLAM FLOATING ROOF FOR STORAGE TANKS Filed June 16, 1932 2 Sheets-Sheet 1 INVENTOR. M @0114 I11 BY A; f.- MATTORNEY- m/liam G.

Feb. 23, 1937. w, 'G MCULLAM 2,071,552

FLOATING ROOF FOR STORAGE TANKS Filed June 16, 19 32 N TOR.

2 Shets-Sheet 2 Patented Feb. 23, 1 937 FLOATING RQOF FOR STORAGE TANKS William G. McCullam, Elizabeth, H. J., assignor to Standard Oil Development Company, a corporation of Delaware Application June 16, 19321Serial No. 617,566

. GClainis.

This invention relates to improvements in roots or decks for storage tanks, especially those used for volatile liquids such as low boiling petroleum oils (gasoline and the like). Theinventlon is l particularly adapted to the construction of floating roofs but some of the principles of design may be advantageously used in roofs which are secured in place.

A principal object of the invention is to pro- 10 vide a roof of light weight, self-buoyant-materlal, for example, balsa wood or equivalent wood. The roof is made up of laminations and is suitably oilwaterand fire-proofed as described herein.

Another object of the invention is toimprove II the fastening means used to hold the seal on'the' floating roof.

Another object of the invention isto provide means for securing a floating root in an elevated position when it is desired to inspect or .clean.

s the tank below the roof level.

Further objectsand-advantages of the-invention will be apparent from the following description read in connection with the accompanying drawings, in which Fig. 1 is a top plan view oi a storage tank pro vided with a floating roof made according to this invention. r I

Fig. 2 is an enlarged vertical section on line 2-4 of Fig. 1.

Fig. 3 is a similar view indicating alternative methods securing the laminations on the roof together.

Figs. .4, 5'and 6 are plan views showing a preferred way of laying out sections for the building 35 up of 'the'floating roof.

Fig. '7 is a view similar to Fig. 2 showing an alternative method of building up the laminated structure.

Fig. 8 is a vertical section through the edge of the roof showing the sealing ring and the means for securing the ring to the root.

Fig. 9 is a vertical section on line 9-9 of Fig 8.

Fig. 10 is a view similar to Fig. 8 but indicating the connection of the ring retaininz means with a roller for guiding the up and down movement oi the floating roof, and

Fig. 11 is -a section through the roof and the tank indicating the means for sustaining the.

root in an elevated position.

5o Referring first to Figs. 1 and 2, reference number lindicates the side wall of a storage tank, for example, a tank such as .is used for storing gasoline. A floating roof 2 is placed in the tank with the usual clearance between the root and u the wall. ,This clearance is closed by the scaling ring ll hereinafter described. The roof has a manhead 3 of any suitable construction. In genera] the roof will be flat, but other shapes may be adopted.

In accordance with this invention-the body of 5 the roof .s made up of laminations of material such as balsa wood, which is light weight, sellbuoyant in gasoline, and easily treated so as to prevent absorption of gasoline. As shown in Fig.

2, three layers of balsa wood 4, 5 and 6, are pro- 10 vided, each layer being made of .strips which are laidat an angle to the layer next beneath. The layers are secured together by oil-proof and water-prooi marine glue or similar material. A supporting structure in the form oi battens l of 5 white pine or the like .is provided. As shown in Fig. 1 these battens are arranged in the form of a grid beneath the laminations. Suitable cross joints are provided where the battens intersect. The battens are secured to the bottom layer of the roof by aluminum nails 8' or in any other suitable way.

.adjacent, or,hardwood dowel strips 9 may be inserted through the layers. The opening above the strip may be covered with plastic wood Ill. 7 When large roofs are'to be constructed it is necessary to build it up of sections of laminated wood. A desirable pattern for these sections is g indicated respectively II, I! and"-13 in Figs. 4, 5 and 6. For example, in a rooi' having a diameter of 59'2", it is desirable to provide 16 sections as inFigs. 4 and 8 each as in Figs. 5 and 6. i The entire root is preferably painted with a phenol-formaldehyde coating or equivalent material so as to make the wood impervious to oil and water. Additional rotection against absorption 40 of liquids may be provided in the form of thin metal sheets to and 50 (Fig. 7) inserted between the laminations. It is desirable to fire-proof the roof by suitable means such as a thin metal cover 6a with joints crimped or welded.

The preferred type'of sealing means between the tank wall and therooi! as shown in Figs. 8. 9 and 10, is a ring it of leather, rubber, or other resilient-material such as is commonly used in sealsoi' this type. 'The'means provided by the present invention are in the mannerof securing the ring. to the roof. For this purpose a clamp in general s-shaped designated I5 is provided. The bottom turn of the clamp has teeth i6 adapted'to sink into the loweriaycr of the roof. The middle a the S-shape clampismodifledso as toserveas a.

support for a roller II. This roller is adapted to run, on guides as is usual in the construction of floating roofs. In this figure, 22 indicates the clamping means and 23 the extension comprisinga bearing 24 in which the shaft of the wheel turns.

An aluminum wedge is is driven between the top of the roof and the bottom of extension 23 to hold the wheel in proper position. In Fig. 11 means are shown for supporting the roof at aconvenient height so that men may work beneath it to clean out the tank. This means comprises V-shape supports 20 secured to the under surface of the roof. In the bottom of the tank are secured tressels 21 by means of bolts fastened to the bot-' tom of the tank. In the ordinary operation the roof will be turned so that the V-shape supports do not make contact with the tressels. However, when it is desired toclean out the tank the roof is turned so thatv when it sinks with the withdrawal of the liquid, the V-shape supports will restontopsofthetres'selsandhold theroof ata convenient height. v

The present invention provides a'satisfactory mofoflowcotwhichcanbeinstalied in tanks even of the largest size. The sectional construction makes fabrication in the field easy. Although reference has been made to specific materials in the illustrative description given above, it will be understood that other woods. metals, and fabrics may be used.

Various changes and alternative arrangements may be made within the scope of the appended claims, in which it is my intention to claim all novelty inherent in the invention as broadly as the prior art permits.

1' claim:

1. A floatable sectional tank roof structure comprising a plurality of sections adapted to be assembled edge to edge so as to form a unitary structure conforming to the contour of the tank walls, each section comprising a plurality of laminae, of which a predominant number are self buoyant, placed one above the other, in angular relationship to one another, means for securing one lamina to the other, means for sealing the laminae against moisture and absorption of material in the tank, and non-ferrous means for securing one section to another.

. 2. A floatable sectional tank roof structure according to claim 1 in which the self buoyant laminae are formed from thin sheets of balsa wood.

3. A floatable sectional tank roof structure 'according to claim 1 in which at least one laminae of each section comprises a thin sheet of nonferrous metal placed between alternate laminae of a self buoyant material.

4. A floatable sectional tank roof structure according to claim 1 in which the means for sealing the laminae against moisture and absorption of liquid in the tank comprises a coating of an oil and water impervious material on each lamina and a thin sheet of fire resistant material secured to the uppermost laminae after the sections have been assembled. a

5. A floatable sectional tank roof structure according to claim 1 in which the non-ferrous means for securing one section to another coin-- prises a plurality of wooden battens in the form of a grid in which the points of intersection of the respective battens is substantially equidistant from all sides of the laminated section immediately above, secured by holding means not in-' cluding iron to the under surface of the roof.

6. A floating roof for storage tanks consisting of a plurality of thin.sheets of a self-buoyant material disposed one above the other, thin sheets of non-absorbent, non-buoyant material disposed between the self-buoyant sheets, a fireproof covering for the exterior of the roog and non-ferrous means for securing one sheet to another to form a unitary. laminated structure.

.WILLIAMQMcCULLAm. 

